1. Field of the Invention
The present invention relates generally to vehicle seats and, more particularly, to vehicle seats having a belt-type lumbar support.
2. Related Art
Many different types of lumbar supports have been used in seating systems. Strap or belt-type lumbar supports can be any type of strap, including a belt or wire, and are known to be supported in the seat frame by various means, including springs, hooks, brackets, clips, and wires. Strap lumbar supports are also known to be operated using a number of different actuation devices. Examples of prior art strap lumbar devices can be found in the following references: U.S. Pat. Nos. 3,258,259, 3,273,877, 4,155,592, 5,716,098, EP 0296938, EP 0420824, EP 0540481, CA 2450735, FR 2596334, and FR 2765531.
Strap lumbar devices can usually be distinguished from arching lumbar devices, such as described and illustrated in U.S. Pat. Nos. 6,003,941 and 5,518,294, based on the difference between their respective tensioning elements. The strap lumbar is connected to the seat frame in a manner that the tensioning element, either the strap itself or that supports the strap, must be pulled taut to increase support. In comparison, the tensioning element in the arching lumbar is stiff and can be rotated, pushed or bowed to increase support.
Although the prior art devices have adequately provided lumbar support, some problems still remain. As a first example, the spring or cable of the strap-type lumbar support may wear, dig into, or catch upon the seat back foam causing the seat back foam to prematurely fail. As a second example, the belt-type lumbar support may twist or turn during installation or when in use by a seat occupant. The rotation or twisting of the belt-type lumbar support causes great difficulty in installation and may cause discomfort to the seat occupant.
Modular seat assembly techniques require seat interior components to be designed for ease and speed of assembly. Modular lumbar supports often include vertical extensions. In both assembly and finished use, the extra leverage such extensions place on anchors causes undesirable wear and binding.
Therefore, there is a need in the art for an improved belt-type lumbar support that does not affect the wear characteristics of the seat back foam. Further, there is a need in the art for an improved belt-type lumbar support that is rotationally fixed. Finally, along with the need for strong, economical, compact components in seat design, there is a continuing need in seat assembly procedures to increase the economy, speed and efficiency of component assembly and shipping.